The present invention relates to a closure for a fuel tank of a motor vehicle having a closure cap fastenable in a liquid-tight or gas-tight manner to a filler pipe. The closure cap has an upper part being in contact with a seating surface of the filter pipe via an annular seating surface fitted with a flat seal and having on the cap part an axially projecting insertion part that is fastenable in an axially direction on the filler pipe.
Known closures for fuel tanks of motor vehicles are connected with the filler pipe by means of either a screw or bayonet connection, by executing an inserting and rotating motion. Such closure motions are relatively awkward and complicated for automatic refueling systems to perform.
It is an object of the present invention to provide a closure of the type mentioned above for a fuel tank of a motor vehicle, wherein the closure cap is axially fastenable on the filler pipe by executing a simpler movement.
To achieve this object a closure of the above mentioned type for a fuel tank on a motor vehicle is provided according to which the insertion part is provided with a contacting element that can be moved back and forth relative to an undercut or counter-profile in the filler pipe.
By virtue of the measures according to the present invention, the fastening movement of the contacting element in the filler pipe is derived from the motion of inserting the insertion part into the filler pipe. As a result, a robot, for example, needs only to execute a simple movement in order to insert and fasten the closure cap in the filler pipe, or to detach and remove it from the filler pipe.
In a first preferred embodiment of the present invention, the contacting element is pivotally attached to the insertion point. In a further embodiment, provision is made for the contacting element to be a leg spring whose pivoting motion is derived from the axial motion of a sliding element. In other words, the motion of inserting the insertion part tensions the leg spring in such a manner that one of its legs is in contact against a lower edge of the filler pipe while its other leg is in contact against the outside of the plunger. In this way, the cap part, which is rigidly linked with the pivoting axis of the leg spring, is actively forced downwards and against the seating surface of the filler pipe. The axial excursion of the plunger out of the insertion part takes with it the second leg of the leg spring and thus causes the leg spring to pivot, thereby detaching itself from the filler pipe. Since the leg spring is then located within the insertion part, the entire closure cap can be removed from the filler pipe.
In accordance with a second and third embodiment of the present invention, the contacting element is radially movable and, according to, the arrangement whereby the contacting element is made up of radially movable bolts or a radially displaceable sealing ring, or also two thereof arranged one above the other, are provided. Preferred variants and embodiments in this respect are found in that the radial bolts are in contact with a lower edge of the filler pipe, or in that the sealing ring projects radially into a circumferential channel.
The movement of the radial bolt or sealing ring is obtained when the insertion part is made up of several elements and that the radial movement of the bolt or sealing ring is brought about by a radial relative movement between the individual elements of the insertion part or in that the radial movement of the bolt or sealing ring is brought about by a relative movement between the cap part and the insertion part, or in that, at its end, the insertion part is fitted with a sealing ring that is in radial contact with an area of the inner wall of the filler pipe, or in that the relative movement between the cap part and the insertion part and/or between the individual elements of the insertion part is brought about by means of a lever preferably a rocker lever or eccentric lever, or in that the relative movement between the cap part and the insertion part and/or between the individual elements of the insertion part is achieved by a rotating driving motion, or in that one element of the movement mechanism is connected to an individual element of the insertion part and the other element of the movement mechanism is rotatably or pivotably attached to the other element and abuts against the cap part.
The features whereby the circumferential edge of the cap part is arranged within a establishing edge of the filler pipe, the stabilizing edge surrounding and projecting above the seating surface of the filler pipe provided greater security to the extent that, in the event of a crash occurring ill this area of the motor vehicle, the closure cap is protected by the stabilizing edge of the filler pipe, so that in this case the cap is prevented from becoming detached.
In order to further simplify operation in those vehicles whose filler pipe is additionally covered over by a flap in the bodywork, which is almost always the case, a closure cap movably connected with the flap are preferably provided. By this means, when the flap is opened or closed fi-om outside, the closure cap can also be brought into the closed position in the filler pipe, or it can be removed again from the pipe. This can be accomplished in a wide variety of ways, for example by an electrical, pneumatic or similar connection. In accordance with an arrangement whereby the closure cap is connected with the flap, a mechanical connection in the form of a lever linkage is provided. In order also to guarantee safety in a crash, the lever linkage possessing a predetermined breaking point is provided. By this means, the flap becomes detached from the closure cap if there is any deformation of the bodywork in this area, so that the cap remains attached to the filler pipe.
According to a further preferred embodiment, the movement of the contacting element relative to the undercut or counter-profile of the filler pipe is taken from a thermochemical metal hydride actuator or from a thermal expansion element actuator. This additionally means that the insertion part can be fastened in or detached fi-om the filler pipe in a simple manner via a remote-controlled locking and unlocking system. In other words, in order to unlock or detach the insertion part from the filler pipe, the metal hydride actuator or the expansion-type actuator is thermally activated so that the closure can be removed by the robot, then following refueling and reinsertion of the insertion part in the filler pipe it can again be thermally deactivated, as a result of which a locking action takes place.
The thermal activation can be advantageously accomplished electrically via a thermal resistor, so that this procedure can be very simply initiated from inside the vehicle by operating a switch, or from any desired position by means of remote control.
The contacting element and the way in which it is moved can take many forms. For example, the movement and sealing action of the contacting element or its radially movable bolt can be configured according to the features whereby the bolts are connected with each other by an articulated lever arrangement which is moved by an actuator, or whereby the articulated lever arrangement on the side facing away from the actuator is acted on by a pressure spring, or whereby the bolts are acted on radially at their inner surfaces, and via an inclined arrangement of sliding surfaces by an axially movable positioning element driven by an actuator, or whereby the bolts are acted on at both sides by the oppositely inclined arrangements of sliding surfaces.
The way in which movement is imparted to one or more of the sealing rings of the contacting element and the arrangement of such ring or rings can be configured in that the sealing ring is mounted between the insertion part and the cap part which is axially movable relative thereto, and that between the cap part and the insertion part there is provided the actuator, and/or, in that an annular element is mounted between the cap part and the insertion part, and between this annular element and the cap part on the one hand and between the annular element and the insert part on the other hand, with a sealing ring arranged in each case.